13:I[3609,["866","static/chunks/e37a0b60-550bec2f415953d4.js","231","static/chunks/231-0a4ae3062bfb7455.js","856","static/chunks/856-c8b30bf8b64887ca.js","581","static/chunks/581-49d6aa9a8ce70804.js","809","static/chunks/809-4acc7e8800bc801b.js","455","static/chunks/455-98a0e594167a035d.js","40","static/chunks/40-ae71f548990caa99.js","877","static/chunks/app/%5B...slug%5D/page-45ad80e813b8b571.js"],"default"] 14:T48d,

Topic B focuses on spatial relationships and structuring as students organize equal groups (from Topic A) into rectangular arrays. They build small arrays (up to 5 by 5) and use repeated addition of the number in each row or column (i.e., group) to find the total.

In Lesson 5, students compose arrays either one row or one column at a time and count to find the total using the scattered sets from Topic A. This is foundational to the spatial structuring students need to discern a row or column as a single entity, or unit, when working with tiled arrays without gaps and overlaps in Topic C. In Lesson 6, students decompose one array by both rows and columns. In Lesson 7, students move to the pictorial as they use math drawings to represent arrays and relate the drawings to repeated addition. In Lesson 8, students work with square tiles to create arrays with gaps, composing the arrays from parts to whole, either one row or one column at a time. In Lesson 9, students apply the work of Topic B to word problems involving repeated addition (shown below), interpreting array situations as either rows or columns and using the RDW process.

15:T606,

Second Grade mathematics is about
- Extending understanding of base-ten notation
- Building fluency with addition and subtraction
- Using standard units of measure
- Describing and analyzing shapes

About Downloadable Resources

A Story of Units: Curriculum Map and Overview for Grades P-5: provides teachers with a clear picture of the modules at each grade

Topic b - Arrays and equal groups